The prior art of bearing structure for the blade assemble of the cooling fan mainly consists of a bearing, an oil seal, a washer and a circlip. It usually takes a great lot of time, labor, material and cost to assemble. Under long time rotation, it is inevitable that the bearing will generate much noise, run unsmooth and shorten the service life. Now a magnetic levitation motor is introduced in an effort to reduce the parts and noise and to promote the precision and longer service life.
FIG. 8 shows a magnetic levitation motor used on the cooling fan. Technically, the blade 1′ has a recess to receive the magnet 11′ and the circuit board 2′ on which a magnetic levitator 21′ is mounted to produce an angle of 90° vertical magnetic levitation attraction as the arrow indicates and the blade 1′ is therefore attracted. The rotor winding 22′ and the magnet 11′ will induce a magnetic rotation forcing the blade 1′ and the rotor shaft 12′ to make a suspending rotation in the space. The magnetic levitation motor has broken the bottleneck inhered in the conventional motor and overcome the noise, abrasion and short service life.
However, the magnetic levitation motor mounted on the cooling fan presents a low yield rate in production because the blade 1′ and the magnetic levitator 21′ must be disposed at 90 degree, if the degree is deflection, the blade 1′ will not be rotating smooth. So, the magnetic levitator 21′ must be places in exact parallel to the magnet 11′, relatively, the rotor shaft 12′ of the blade 1′when inserted must be kept in parallel with magnet 11′ and the magnetic levitator 21′. Because of the high precision in assembly, the lows yield rate hurts the production.